Process and apparatus for refining silicon
CA 2200166 C · Owner: Abe, Masamichi · Inventors: Baba, Hiroyuki; Yuge, Noriyoshi; Sakaguchi, Yasuhiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process and apparatus for refining silicon by treatment in a graphite vessel with irradiation with an electron beam while removing impurity elements by evaporation. A single graphite vessel is used or plural, graphite vessels are arranged in sequence. During treatment in successive graphite vessels molten silicon, is poured in succession from one vessel to another. Use of graphite vessels improves heat efficiency prevents, contamination and produces refined silicon containing very low contents of impurities.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed March 17, 1997 and granted January 22, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 17, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 17, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.